A minimal framework that supports the implementation of WebSocket
extensions in a way that's decoupled from the main protocol. This
library aims to allow a WebSocket extension to be written and used with
any protocol library, by defining abstract representations of frames and
messages that allow modules to co-operate.

websocket-extensions provides a container for registering extension
plugins, and provides all the functions required to negotiate which
extensions to use during a session via the Sec-WebSocket-Extensions
header. By implementing the APIs defined in this document, an extension
may be used by any WebSocket library based on this framework.
